In a fabrication apparatus that handles planar workpieces, such as panels, sheets, semiconductor wafers, etc., or planar members, such as photomasks, etc., and more particularly, in a fabrication apparatus that processes and laminates together liquid crystal, electronic paper, organic EL, or like members or that processes and assembles circuit substrates, or in a fabrication apparatus for a semiconductor integrated circuit or the like, the alignment of such planar workpieces or members is performed by automatically detecting their positions. For simplicity, in the description given herein, workpieces such as panels, sheets, substrates, semiconductor wafers, etc., and members such as photomasks, etc., on the fabrication apparatus side, may be simply referred to as “workpieces”.
Japanese Laid-open Patent Publications No. 2002-243412 and No. 2005-317806 each disclose a method for alignment of a printed substrate and a glass plate by detecting marks provided on the printed substrate and the glass plate, respectively. Japanese Laid-open Patent Publication No. 2006-119321 discloses a structure in which alignment marks are provided on a liquid crystal display panel and a flexible substrate, respectively, for alignment of these two members. Japanese Laid-open Patent Publication No. 2006-5187 discloses a method for detecting the orientation of a printed substrate by using a plurality of positioning marks.